Troubleshooting Astro City with stock Nanao MS8-29/Toshiba tube

astrocitynoob

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Troubleshooting Astro City with stock Nanao MS8-29/Toshiba tube

Hi all,

I recently purchased my first candy cab, a stock Astro City. Apologies in advance for the long post -- just want to make sure I explain everything correctly.

The person who sold it to me noted a problem with the monitor, and that there was a "trick" to get it working. Upon initial powerup, the cabinet and board would boot up fine, but the monitor would stay blank. He thought it had to do with a failing capacitor taking time to charge. After a few minutes, you would cycle the power on/off, and repeat until the tube would come on. The boards booted fine and you'd hear sound and what not, just no picture. I verified this when picking it up, and figured I'd have it looked at later.

After getting the cabinet to my place, I plugged in a board and fired the thing up. No picture, as expected. After a few restarts, the tube came on, but the picture was distorted, lots of snow and fuzziness. I fiddled with the pots on the control board and was able to make out faint sprites from the game, but they were mostly lost in the snow.

I noticed the horizontal size didn't seem to go to the edges of the screen even when the pot was maxed, and kept fiddling with it. After a few minutes, the screen instantly snapped into perfect focus/picture. I twisted it again and it returned to snow, and then lost picture entirely.

Now the tube shows no picture no matter what I do. At this point, it doesn't even appear to be powering on (no whine/static). A friend who owns two Astro City cabs came over and brought a spare MS9-29 to install, but it was missing the control board so we weren't able to install it. We did however take out the monitor and look over it, dusted and cleaned it off. We checked for bad caps and didn't see anything, and attempted to power the monitor outside of the cabinet to no avail.

So as it stands, the tube doesn't appear to get a picture or power up at all. It's possible during moving something was knocked loose or the monitor was failing and finally failed (as evidenced by the pre-existing issue).

Does anyone have advice for troubleshooting or repair? What should my next steps be? Send the chassis off to be inspected/repaired? Recap it myself? Buy a new chassis?

FWIW, I'm in the New York City metro area. Happy to pay an experienced arcade monitor technician or candy cab enthusiast to check it out and fix it if you're nearby.

Thanks for reading!

PS: Going to cross-post this to a few other forums. Sorry if you've seen this post elsewhere!
 
Sounds like a faulty trim pot based on your description. Maybe adjusting them may have broken one loose, which would prevent it from coming up. Can you get a flashlight in there and make sure all 3 legs on the pots are still in tact and not twisted/bent out of shape or broke?
 
Sounds like a faulty trim pot based on your description. Maybe adjusting them may have broken one loose, which would prevent it from coming up. Can you get a flashlight in there and make sure all 3 legs on the pots are still in tact and not twisted/bent out of shape or broke?

I was making adjustments via the control board, not on the chassis itself. None of the chassis pots looked out of the ordinary yesterday, and I just looked over the control board backside and noticed it was a bit dirty and maybe Hsize had overheated, but everything looked normal. Tried powering the cabinet again and still no picture and it doesn't appear that the tube is coming on at all (no whining noise, static, etc).
 
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